Apparatus for the production of artificial threads and the like



Feb. 13, 1934. H. HOFMANN 1,947,159

APPARATUS FOR THE PRODUCTION OF ARTIFICIAL THREADS AND THE LIKE FiledDec. 16, 1951 if w Patented Feb. 13, 1934 ENETED STATES hATENl FFEQEAPPARATUS FOR THE PRODUCTION OF ARTIFICIAL THREADS AND THE LIKEApplication December 16, 1931 Serial No. 581,475

1 Claim.

My present invention has to do with the manufacture of artificial silkand the like, and more particularly with the provision of suitable meanswhich will increase both the quality and quan- 5 tity of the threadproduced.

One object of my present invention is to provide a novel form of outletfor the spinning funnel which will prevent the formation of air bubbleswhich are likely to harm the freshly 1 extruded filaments or thread.

Another object of my present invention is to so construct the outlet ofthe spinning funnel that the amount of coagulating or hardening liquidused may be readily controlled.

15 A further object of my present invention is to so form the outlet forthe spinning funnel that the salts which are precipitated during thespinning process will not aiTect in any way the production of theartificial thread or filaments.

20 These and other objects of my present invention will become moreapparent from a study of the following description and of the drawing inwhich:

Figure 1 is a partial sectional view of the spin- 25. ning mechanism;

Figure 2 is a detailed view of the outlet or nipple shown in Figure 1;

Figure 3 is a side elevation of a modified form of the outlet or nipple;

Figure 4 is an end elevation of the same;

Figure 5 is a side elevation of a further modification of the outlet ornipple; and

Figure 6 is an end elevation of the same.

Referring now to the drawing, and more par- 35 ticularly to Figures 1and 2, I have shown a spinning chamber 10 having a head 11. This head isprovided with a spinneret 12 to which a suitable spinning solution isled by the pipe 13. A funnel 14 is located in the spinning cham- 40,beer and is held in place by a casting or ring 15 secured to saidchamber. The casting or ring is provided with an inlet 16 for thecoagulating or hardening liquid and is also provided with openings (notshown) through which the 45 coagulating or hardening liquid enters thespinning chamber between the walls of said chamber and the funnel.

The funnel comprises a funnel-like portion 14 secured in the spinningchamber which tapers 50. into a tube 1'7. To the end of this tube issecured, by any convenient means, a nipple or outlet tube 18 shown indetail in Figures 2 and 3. The nipple or outlet tube comprises a U-shaped portion 19, the leg 20 of which termimates in a widened openingor flared portion 21.

As may be seen from an inspection of Figure 2 the nipple is providedwith an inwardly projecting portion 22 forming a guiding surface for thefilaments and which will hold them from contacting with the Wall of thetube, thus re- 60, ducing friction.

The spinning solution is forced through the spinneret into the hardeningor coagulating bath contained in the spinning chamber. The liquid andthe freshly spun filaments move downward- 65. ly through the funnel,such action imparting a stretch to the filaments. The filaments thenpass through the U-shaped nipple 22 over the acid guides 25, secured toa reciprocating bar 23 and wound on a suitable receiver, such as a reel24.

, As will be seen from the drawing, the usual level of the treatingliquid in the U-shaped tube is designated by L- L. The liquid in thatportion of the tube thus forms a liquid pocket or seal which effectivelyprevents air bubbles from passing into the funnel. Should the flow ofthe treating or hardening liquid be temporarily or suddenly shut off,the liquid in the U-portion of the tube would be sufficient to form 8usable filaments. As is well known, great difficulty has beenexperienced in the formation of air bubbles since they tend to injure orrupture the freshly spun filaments resulting in the formation of lowgrade yarn. Moreover, since because of the shutting oil of the supply oftreating liquid, according to existing devices, no filaments would beformed, but on the contrary, the cellulosic spinning solution wouldcontinue to be forced into the spinning chamber and consequently wouldnecessitate a complete cleaning of the same before reuse. If theextrusion of the spinning solution were, or could be, stopped at thesame time that the fiow of treating liquid ceased there would still beconsiderable time wasted in the restarting of the spinning operation.This would be due to the fact that the cellulosic solution in the nozzlewould become hardened by contact with the air thus resulting in aconsiderable period of time to be wasted in the cleaning thereof. Withmy present invention sufficient hardening liquid would be present toavoid the shutting down or clogging of the mechanism.

The outlet end of the U-shaped tube is Wid- 5 ened as described before.Since the cellulose of the spinning solution before extrusion isdissolved in a cuprammonium solution, the copper thereof is precipitatedout in the form of salts by the hardening liquid. In the usual form 9 offunnel now in use the exit end thereof soon becomes restricted by thedepositing of these salts at that point retarding the rate of flow ofthe hardening or coagulating; liquid. This results in the formation of apeer thread. By the use of my present invention the outlet is largerequiring the removal of the deposited salts at stated intervals only.Since the amount of liquid necessary to harden the liquid and designatedby L-L' is trapped in the iJ-portion of the nipple the fact that theoutlet may become restricted in size does not affect the formation ofthe filaments.

In Figures 3 and 4, I have disclosed a modified form of nipple oroutlet. In this modification the U-portion 19' is provided with agrooved guiding section 26, the function of which is to cause a slightcompacting of the thread or filament. Should it be desired to form asoft thread, a fiat guiding surface, such as is formed by the portion22, would be used to spread the filaments. The bend of the lJ-portion ofthe filament is of considerable length, so that when only a small amountor" coagulating or hardening liquid is in the funnel and the level isreduced to L-L because of a temporary failure of the liquid supply, orfor any other reason, there will be suflicient liquid yet remaining inthe nipple or outlet to produce a satisfactory thread.

In Figures 4 and 5 I have shown a form of nipple or outlet which isprovided with a U- shaped guiding surface 26 similar to that shown inFigures 3 and 4. This nipple or outlet functions in a manner similar tothat of Figures 1 and 2 but forms a hard thread rather than the softthread formed by the use of the nipple or outlet shown in Figures 1 and2.

Although I have described three preferred forms of my invention it isobvious to one skilled in th art that many mechanical variations may bemade without departing from the spirit of my invention. I wish ittherefore to be understood that my invention is to be limited only bythe scope of the appended claim.

What I claim is:

In an outlet tube for use with a funnel for the production or"artificial filaments, a straight tube portion, the lower end or" whichis bent to form a U and the exit orifice of which is flared, the saidtube at the beginning of the bend being depressed to provide an inwardlyextending curved portion, the convex side thereof facing thebeforeinentioned dared orifice whereby the filaments passing downwardlythrough the straight tube portion are held out of contact with the sidesthereof, the U-portion having a guiding cons ricting surface serving tocompact filaments.

HUGO HOFMANN.

